Corporal T. Rymann was a Non-commissioned officer in the UNSC Marine Corps and an Orbital Drop Shock Trooper who served during the Human-Covenant war. He was part of Alpha Team of the 2BN/3U as Bravo-21 with Bravo-22, S. Hartley.
He participated in the Battle of Sector Six during the Battle of Earth, covering his comrade as he retrieved what seemed to be the same Long Range Scanner that his partner, S. Hartley, used to track John-117 on his descent to the planet's surface. Bravo-21 was almost killed by a Fuel Rod Cannon strike from a strafing Banshee flier. A Pelican dropped off a Warthog, prompting the ODSTs to make a run for the middle of an exposed area. Bravo-21 took the driver's seat while Bravo-22 had taken the passenger seat. As he drove away, Hartley was hit in the abdomen by a Spiker. Right after that, the Warthog crashed through a wall.
After driving down a highway to Sector Six, Bravo-21 made his way towards a squad of Marines as they were holding off numerous Jiralhanae. After arriving, he helped his comrade out of the Warthog as Corpsman R. Coney treated Bravo-22. He then moved towards a few Marines near cover. After listening to a sit-rep, he took a SRS99D-S2 AM Sniper Rifle and repelled a squad of Brutes attempting to flank the Marines' position. He ordered the Marines to hold their ground, as it was a vital location to their objective, which was to locate the Master Chief entering Earth's atmosphere in order to make a possible extraction for the SPARTAN.
His first two shots were immediately fatal. Right after firing a third round, T. Rymann heard a growl and turned to see that he was being attacked by a Jiralhanae Chieftain wielding a Gravity Hammer. After dropping the sniper rifle and dodging the first swing, Bravo-21 tried to flee as he avoided a Spike Grenade, which missed him and impacted a nearby wall, then fell over a bump on the ground while facing the chieftain. However, he took his M6G sidearm out of his abdomen holster and fired a single shot. The Brute swung again, striking Rymann in the chest and knocking him against a wall, spraying his blood against the cement. As Rymann fell to the ground, injured, the Chieftain swung again, crushing the Shock Trooper's body with the hammer, instantly killing him.
The Chieftain who killed Rymann was killed himself when one of the retreating Marines shot him with a rocket launcher. After his death, when the remaining Marines retreated, Rymann's body was left out on the battlefield. It is unknown if it was retrieved or not, but it is probable that it was after the area was cleared.
- According to his medical reference patch, Rymann possessed O+ blood.
- T. Rymann was the only known ODST to have an M6G holster on his abdomen.
- Unlike most ODSTs' helmets, Rymann's visor was tinted red instead of blue.